Carriers in the US are notorious for often, if not always being late with updating their devices to the latest version of Android, creating huge delays sometimes before their devices see such updates. Those owning the T-Mobile Galaxy S2 SGH-T989 can stop waiting for T-Mobile to push the official Ice Cream Sandwich update to their phones, and update to it unofficially by flashing an AOSP based ROM, simply named ICS 4.0.3, by recognized XDA developer RaverX3X.

Keep in mind that the ROM is under development, and so bugs and issues are to be expected. Reporting those bugs and any problems you encounter to the developer should help in getting those issues resolved, so do try to do so if possible.

Read on to find out how you can update your T-Mobile Galaxy S2 to Ice Cream Sandwich unofficially with ICS 4.0.3.

Compatibility

This ROM and the guide below are compatible only and only with the T-Mobile Galaxy S2, model number SGH-T989. It’s not compatible with any other device, including other US variants of S2, the Epic 4G Touch, and AT&T Galaxy S2 along with Skyrocket. Check your device’s model number in Settings» About phone.

Warning!

The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.

How to Install ICS 4.0.3 on T-Mobile Galaxy S2

Transfer the zip file downloaded in step 1 to the internal SD card on your phone.

Turn off the phone, then boot into recovery mode. For this, press and hold these 3 buttons together until the screen turns on: Volume UP + Volume Down + Power. Phone will boot into CWM recovery. Use volume keys to scroll up and down between options and power/home key to select an option.

[Optional] Perform a Nandroid Backup of your existing ROM, so that you can always restore it from recovery if something does not work out with this rom. To perform a backup, select Backup and Restore –> On the next screen, select Backup again. Restore your backup using the restore option when needed. Go back to main recovery menu after backup is complete.

Select wipe data/factory reset, then select Yes on next screen to confirm. Wait a while till the data wipe is complete. This does not erase your personal files on the SD cards.

Now select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the sdcard and select it. Confirm installation by selecting Yes – Install ______.zip on the next screen. The ROM will start installing.

After the installation is complete, select go back then select reboot system now to reboot the phone.

Wait a while for the first boot to complete, then enjoy Ice Cream Sandwich Android 4.0.3 on your T-Mobile Galaxy S2. Visit the original development page for more info and to get the latest updates on the ROM. Share your thoughts on the ROM in the comments.